Hot molding composition



Patented Dec. 4, 1934 TESI' PATENT oFncE HOT MOLDING Oscar A. Cherry, Chicago, 111.,

COMPOSITION assignor to Economy Fuse & Manufacturing Company, Chicago, 111., a corporation of New York No Drawings.

This invention relates to a new and improved molding composition of the phenolic condensation type, particularly char of an additional substance 5 part improved molding properties thereto.

acterized by the inclusion which serves to im- It is customary and desirable, in the manufacture of hot molding compositions derived from phenol resins or pot densation products, to add, at

bricating agent.

The function of this the sticking of prevent entially reactive phenolic consome stage, a lulubricating agent is to the composition or the molded object to the hot metal molds.

Such a. lubricant, for best results, must possess certain properties. nature that its presence in It should be of such a the molded objects made from the composition must not result in an impairment of the norm or electrical resistivities.

al physical, chemical The lubricant must be without any chemical action on the molds ordinarily employed for the hot pressing operations.

Preferably the lubricating agent should be substantially wat It has also been er-insoluble.

the practice in preparing hot molding compositions from phenolic condensation products to add plasticizing agents. The function of these agents is to increase the thermoplastic fiow of these materials or to retard the moment of final hardening under the influence of heat and pressure.

In this case, too, it is ticizing agent be of such desirable that the plasa nature that the desirable properties of the molded material are not impaired.

calcium stearate.

Stearic acid has a tendency to etch the steel molds in which the compositions are ordinarily molded and is thus objectionable.

Calcium stearate or other metallic soaps are free from this objection but the use of too large a quantity results in decreased lent lubricating prop strength. Waxes have excelerties but the use of them except in very small quantities results in a loss of strength.

Recently a compound of butyl alcohol and stearic acid, i. e.,

butyl stearate. has been proposed as a lubricant and water-proofing agent for this type of composition. Molding compositions containing more than a very small quantity of butyl stearate, do not form articles having a good appearance, due to ate and the formation of a greasy film upon the the separation of butyl stear- Application April 28, 1930, erial No. 448,159

2 Claims. (01. 106'-22) pounds differ among themselves in their ability the potentially reactive phenolic conto plasticize densation products. None, however, possess any lubricating properties.

In the copending applications of Oscar A. Cherry and Franz Kurath, bearing Serial Numbers 266,114, now Patent 1,800,815, filed March 30, 1928, 386,484 now Patent 1,896,069 and 386,486, filed August 16th, 1929, various new compositions of matter have been described and claimed, and their use has been claimed in hot molding compositions for plasticizing or lubricating purposes, or both. One of these products so claimed is'stearanilide, or broadly, any reaction product of stearic or similar acid and an arcmatic amine.

Another class of products so claimed is the result of the successive reaction of an organic acid containing more than six carbon. atoms and an aldehyde upon an aromatic amine. This larger class of products may have plasticizing or lubricating properties, or both. All are apparently soluble in the final infusible condensation prod uct.

Another class of compounds has now been discovered to have both plasticizing and lubricating effects when incorporated in phenolic hot molding compositions. Such compounds are the esters obtained by reacting the chloride or anhydride of saturated aliphatic acid containing more than ten carbon atoms with a phenol. A specific example is phenyl stearate.

The amount of such compound which may be added without deleteriously affecting the molding composition or the molded objects is not definitely known. It is believed that the amount is quite large and in any event, the amount which can be so added is in excess of that necessitated in any ordinary case by lubricating or plasticizing requirements. Applicant has used as high as 7 /2 of phenyl stearate, the proportion being based on the phenolic condensation product.

If lubricating effects only are desired, it is necessary, as a rule, to use not over 1% of phenyl stearate. Very good plasticizing effects may be obtained by the use of 3% ester.

The advantage of using a lubricating agent plasticizing agents heretofore proposed.

I have mentioned phenyl stearate specifically, but it will be obvious to those skilled in the art that other phenols and other acids of the class training more than ten carbon 

